Technical Field
Embodiments of the subject matter disclosed herein generally relate to perforating guns and associated fracturing operations, and more specifically, to methods and systems for activating a setting tool to plug a well.
Discussion of the Background
In the oil and gas field, once a well 100 is drilled to a desired depth H relative to the surface 110, as illustrated in FIG. 1, and the casing 102 protecting the wellbore 104 has been installed and cemented in place, it is time to connect the wellbore 104 to the subterranean formation 106 to extract the oil and/or gas. This process of connecting the wellbore to the subterranean formation may include a step of plugging the well with a plug 112, a step of perforating the casing 102 with a perforating gun assembly 114 such that various channels 116 are formed to connect the subterranean formation to the inside of the casing 102, a step of removing the perforating gun assembly, and a step of fracturing the various channels 116.
Some of these steps require to lower in the well 100 a wireline 118, which is electrically and mechanically connected to the perforating gun assembly 114, and to activate the gun assembly and/or a setting tool 120 attached to the perforating gun assembly. Setting tool 120 is configured to hold plug 112 prior to plugging the well. FIG. 1 shows the setting tool 120 disconnected from the plug 112, indicating that the plug has been set in the casing and the setting tool 120 has been disconnected from the plug 112.
FIG. 1 shows the wireline 118, which includes at least one electrical connector, being connected to a control interface 122, located on the ground 110, above the well 100. An operator of the control interface may send electrical signals to the perforating gun assembly and/or setting tool for (1) setting the plug 112 and (2) disconnecting the setting tool from the plug. A fluid 124, (e.g., water, water and sand, fracturing fluid, etc.) may be pumped by a pumping system 126, down the well, for moving the perforating gun assembly and the setting tool to a desired location, e.g., where the plug 112 needs to be deployed, and also for fracturing purposes.
The above operations may be repeated multiple times for perforating the casing at multiple locations, corresponding to different stages of the casing. Note that in this case, multiple plugs 112 and 112′ may be used for isolating the respective stages from each other during the perforating phase and/or fracturing phase.
FIG. 2 shows a traditional perforating gun assembly and setting tool system 200. From left to right, FIG. 2 shows a perforating gun assembly 214, a switch sub 230, an adapter 232, a setting assembly 234, a quick change tool 240, a setting tool 220, a setting tool assembly kit 250, and a plug 212. These devices are mechanically connected to each other in the order shown in the figure. The quick change tool 240 is made of two parts 240A and 240B that can rotate one with respect to the other. This means that there is no need to rotate the perforating gun assembly and the setting tool when connecting them to each other as the quick change tool performs that function. The quick change tool 240 is connected to the perforating gun assembly 214 through the switch sub 230. The switch sub 230 houses a switch (not shown) that activates a detonator 215 of the perforating gun assembly. An igniter 222, which activates the setting tool, is located in a firing head 224 within the setting tool 220.
The system 200 shown in FIG. 2 is not only complex (many parts that have to be connected together, which means valuable time being spent on assembling the tool and not on extracting the oil and gas) and large (which means that the system is expensive as each part requires special manufacturing and care), but also suffers from the following deficiency. To set up the plug 212 (or plug 112 in FIG. 1), the setting tool 220 needs to be actuated. This process involves firing the igniter 222. Flames from the igniter 222 ignite an power charge located in the setting tool, which actuate one or more pistons inside the setting tool. The movement of the one or more pistons inside the setting tool actuates one part of the plug 212 in one direction and another part of the plug in an opposite direction, which sets the plug. However, burning the power charge inside the setting tool results in high pressure smoke and soot. The smoke and/or soot travel through the holder of the igniter to the quick change tool and other components of the system 200. The soot and pressurized smoke can damage some of these components and/or deposit carbon on these components. When the system 200 is brought to the surface and prepared for a new use, while the igniter and the power charge are replaced, the other components of the system 200 may be reused. However, some other components of the system 200 (e.g., electronic parts present inside system 200 or their holders) are now covered in soot (carbon), which would negatively impact the electrical connections inside the system. Thus, a cleaning process is required for all these components prior to adding the new igniter and power charge. This cleaning process is tedious, slowing down the next step of completion and can result in a misrun if not done properly.
Thus, it is desirable to develop an improved perforating gun assembly and setting tool system that is not affected by the soot and smoke produced by the igniter and the power charge, and which can be cleaned up in a shorter period of time for a new deployment in the well.